1. Field of Invention
The invention relates to a disk film layer separation device and, in particular, to a film layer separation device for multilayer disks.
2. Related Art
In disk manufacturing techniques, a common trend is to make disks with larger memory capacities. There are several methods to enlarge the disk capacity. For example, one can decrease the gap between tracks or, alternatively, add more layers onto the disk to increase the memory block area on a disk.
Taking optical disks as an example, they are often made into single-sided but with two or even more layers. The way to make a single-sided double-layer optical disk is as follows. First, a stamper already printed with data is coated with a layer of glue. After drying, it forms a data film with data bits. Afterwards, paste glue (usually UV glue) is applied thereon to combine with a substrate already printed with data. The combined product is then sent through a UV lamp to harden. Finally, the stamper is separated from the substrate, thereby transferring the data film formed with data on the stamper onto the substrate. Therefore, the substrate forms a single-sided optical disk with two layers of data. The formation of multiple data layers is achieved by repeating the above process several times.
During the above process, the quality of the separation of the stamper from the substrate determines whether the data film can be appropriate transferred to the substrate to form a double-layer disk. In other words, the device that separates the stamper and the substrate plays a very important role in the manufacturing process.
Conventional separation devices use plastic substrates as stampers. After pasting the data film, the stamper is separated using a sucking force produced by vacuum. Such vacuum sucking method employs a vacuum sucker, as shown in FIG. 1. On the top surface 11 of the vacuum sucker 10, there are several annular grooves 12, which generate the vacuum sucking force. As clearly seen from the drawing, only the annular grooves produce the sucking force. The top surface 11 in contact with the stamper does not produce sucking force. Through the sucking force, a strong attractive force tears the stamper off the substrate.
Although the vacuum sucker can achieve a stronger attractive force, the sucking force cannot be homogeneously applied to the stamper because it is produced by the annular grooves. Accordingly, the stress is not continuous throughout the stamper. Such discontinuities at certain places will result in bad separation of the film from the substrate.
In observation of the foregoing problems in the prior art, the invention provides a film layer separation device for multi-layer disks. In combination with the manufacturing process that uses metal stampers, an electromagnetic film separation base is employed to produce an attractive force on the stamper for performing the separation. Since the magnetic force produced by the electromagnetic iron can be designed to apply homogeneously onto the whole metal stamper, therefore no discontinuous or local stress would occur in tearing. The invention can make the film on the stamper smoothly separated from the substrate. Moreover, the stamper can be recycled for further uses.
Accordingly to the disclosed techniques, the film layer separation device for multi-layer disks includes a stamper supporter, an electromagnetic attraction device, and a base fixture.
The stamper supporter has a supporting plane for fixing the stamper so that the stamper can perform the data transfer job by having accurate face-to-face matching between the data film and the disk. The stamper can have a positioning mechanism in design to fix the position of the stamper. One surface of the stamper is attracted by an electromagnetic iron; the other surface including the data film directly corresponds to the disk.
The electromagnetic attraction device is used in film pasting and tearing process to attract the stamper. It contains several major portions; namely, one or several magnetic iron cores and their surrounding conductive coils, a base, and a magnetic housing. The conductive coils are imposed with currents to produce electromagnetic forces. The magnetic iron cores enhance the electromagnetic forces produced by the conductive coils. The base supports the magnetic iron cores. The magnetic housing covers the conductive coils. The rim of the base is connected with and fixes the magnetic housing.
The base fixture fixes the whole device, including the stamper supporter and the electromagnetic attraction device. It may or may not include a base fixing part and a push part. The base fixing part fixes the whole separation device. The push part directly connect with the electromagnetic attraction device to push the stamper supporter and the electromagnetic attraction device closer to the disk while transferring the data film, and to pull them away from the disk after the data film transfer.
Further scope of the applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.